Progress MS-18 (Russian: Прогресс МC-18), Russian production No. 447, identified by NASA as Progress 79P, is a Progress spacecraft launched by Roscosmos to resupply the International Space Station (ISS). This is the 170th flight of a Progress spacecraft.

History

The Progress MS is a uncrewed freighter based on the Progress-M featuring improved avionics. This improved variant first launched on 21 December 2015. It has the following improvements:^[3][4][5][6]

• New external compartment that enables it to deploy satellites. Each compartment can hold up to four launch containers. First time installed on Progress MS-03.
• Enhanced redundancy thanks to the addition of a backup system of electrical motors for the docking and sealing mechanism.
• Improved Micrometeoroid (MMOD) protection with additional panels in the cargo compartment.
• Luch Russian relay satellites link capabilities enable telemetry and control even when not in direct view of ground radio stations.
• GNSS autonomous navigation enables real time determination of the status vector and orbital parameters dispensing with the need of ground station orbit determination.
• Real time relative navigation thanks to direct radio data exchange capabilities with the space station.
• New digital radio that enables enhanced TV camera view for the docking operations.
• The Ukrainian Chezara Kvant-V on board radio system and antenna/feeder system has been replaced with a Unified Command Telemetry System (UCTS).
• Replacement of the Kurs A with Kurs NA digital system.

Launch

On 3 February 2021, Roskosmos approved the updated flight program to the International Space Station for 2021, highlighted with the addition of two permanent modules to the Russian Segment of the outpost. A short tourist visit to the ISS at the end of the year also got the green light.^[7]

A Soyuz-2.1a launched Progress MS-18 to the International Space Station from Baikonur Site 31 on 28 October 2021 on a two-day, 36 orbit rendezvous profile.^[8][9][10] If the air leak repairs planned for Zvezda's PrK chamber (delivery of sealing patches aboard Progress MS-16 in February 2021) are successful, then 3 hours 20 minutes after the launch Progress MS-18 will attempt to automatically dock to Zvezda's aft port.^[7]

The vehicle docked to the aft port of the Zvezda Service Module (SM), on 30 October 2021, at 01:31:19 UTC, and will remain in orbit for 215 days, supporting the Expedition 66 mission aboard the ISS.^[11]

Cargo

The Progress MS-18 spacecraft is loaded with 2,439 kg (5,377 lb) of cargo, with 1,509 kg (3,327 lb) of this being dry cargo.^[2]

• Dry cargo: 1,509 kg (3,327 lb)
• Fuel: 470 kg (1,040 lb)
• Oxygen: 40 kg (88 lb)
• Water: 420 kg (930 lb)

Means of attachment of large payloads

It also delivered MLM Means of Attachment of Large payloads to ISS. It is a 4 segment external payload interface called means of attachment of large payloads (Sredstva Krepleniya Krupnogabaritnykh Obyektov, SKKO)^[12][13][14] Once the nadir end of SKKO is soft docked to Nauka and bolted down, the launch locks on SKKO will be released by the spacewalkers to allow it to be unfolded and extended with its joints self locking in the extended position to create a rigid frame. Then the Zenith end of SKKO is soft docked to Nauka and bolted down. The 3 passive payload adapters and the one active payload adapter (i.e. active remote sensing payload like MIR Priroda's Travers Synthetic Aperture Radar) are then outfitted. The SKKO is derived from the setup used on the Priroda module.^[15] SKKO was launched inside the progress and transferred inside to a temporary storage location inside one of the station modules. It will be taken outside and installed on the aft facing side of Nauka during the VKD-59 spacewalk.^[16][17]

Undocking and decay

The Progress MS-18 is scheduled to remain docked at the station till mid 2022, when it will depart with trash and re-enter the Earth's atmosphere for destruction over the South Pacific Ocean.